The present invention relates in general to a method and apparatus for controlling the speed of transportation vehicles to optimize energy efficiency, and, more specifically, to cloud-based computing to define optimal speed profiles based on an identified route and corresponding road conditions such as road grade.
Vehicle manufacturers continually strive to minimize energy consumption for driving a vehicle (e.g., maximizing the distance driven per unit of gas for a gasoline vehicle or unit of electrical charge for an electrically-driven vehicle). Important influences on efficiency include the speed at which the vehicle is driven, road grade variations over the driven route, and traffic conditions. Automatic speed control (i.e., cruise control) systems can have a beneficial impact on fuel economy by reducing the amount of time spent accelerating the vehicle, especially during highway driving. Maintaining a single speed setting during uphill and downhill road grades, however, consumes more fuel than if the vehicle speed is allowed to vary in order to take advantage of road grade variations to optimize fuel consumption. If upcoming changes in road grade are known in advance (such as from GPS-based maps and advance routing), then temporary offsets can be introduced in the speed setting that accordingly improve energy consumption. As a new grade topology is approached, speed changes can be identified and implemented to reduce the energy consumed to traverse it. Due to their limited scope or horizon, however, prior art systems for modifying vehicle speed based on nearby grade changes achieve limited efficiency improvements.